Ecology, Department of Biology, University of Konstanz, Konstanz, 78464, Germany.
Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy Sciences, Changchun, 130102, China.
Ecology. 2020 Dec;101(12):e03187. doi: 10.1002/ecy.3187. Epub 2020 Oct 7.
Sixty year ago, Charles Elton posed that species-rich communities should be more resistant to biological invasion. Still, little is known about which processes could drive the diversity-invasibility relationship. Here we examined whether soil-microbe-mediated apparent competition on alien invaders is more negative when the soil originates from multiple native species. We trained soils with five individually grown native species and used amplicon sequencing to analyze the resulting bacterial and fungal soil communities. We mixed the soils to create trained soils from one, two or four native species. We then grew four alien species separately on these differently trained soils. In the soil-conditioning phase, the five native species built species-specific bacterial and fungal communities in their rhizospheres. In the test phase, it did not matter for biomass of alien plants whether the soil had been trained by one or two native species. However, the alien species achieved 11.7% (95% CI: 3.7-20.1%) less aboveground biomass when grown on soils trained by four native species than on soils trained by two native species. Our results revealed soil-microbes-mediated apparent competition as a mechanism underlying the negative relationship between diversity and invasibility.
六十年前，查尔斯·埃尔顿提出，物种丰富的群落应该更能抵抗生物入侵。然而，对于哪些过程可能驱动多样性-可入侵性关系，我们知之甚少。在这里，我们研究了当土壤来自多个本地物种时，土壤微生物介导的外来入侵生物的表观竞争是否更具负性。我们用五个单独种植的本地物种来训练土壤，并使用扩增子测序来分析由此产生的细菌和真菌土壤群落。我们将土壤混合以从一个、两个或四个本地物种中创建经过训练的土壤。然后，我们将四个外来物种分别在这些经过不同训练的土壤上生长。在土壤调节阶段，五种本地物种在其根际中建立了特定物种的细菌和真菌群落。在测试阶段，对于外来植物的生物量而言，土壤是由两个还是四个本地物种训练的并不重要。然而，当在由四个本地物种训练的土壤上生长时，外来物种的地上生物量比在由两个本地物种训练的土壤上生长时减少了 11.7%（95%CI：3.7-20.1%）。我们的结果揭示了土壤微生物介导的表观竞争是多样性和可入侵性之间负相关的潜在机制。
